Package org.h2.expression.function

Class RandFunction

java.lang.Object

org.h2.expression.Expression

org.h2.expression.function.Function0_1

org.h2.expression.function.RandFunction

All Implemented Interfaces:

NamedExpression, HasSQL, Typed

public final class RandFunction
extends Function0_1

A RAND, SECURE_RAND, or RANDOM_UUID function.

Field Summary

Fields

Modifier and Type	Field	Description
private int	function
private static java.lang.String[]	NAMES
static int	RAND	RAND() (non-standard).
static int	RANDOM_UUID	RANDOM_UUID() (non-standard).
static int	SECURE_RAND	SECURE_RAND() (non-standard).

Fields inherited from class org.h2.expression.function.Function0_1

arg, type

Fields inherited from class org.h2.expression.Expression

AUTO_PARENTHESES, MAP_IN_AGGREGATE, MAP_IN_WINDOW, MAP_INITIAL, WITH_PARENTHESES, WITHOUT_PARENTHESES

Fields inherited from interface org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

Constructor Summary

Constructors

Constructor	Description
RandFunction(Expression arg, int function)

Method Summary

Modifier and Type	Method	Description
java.lang.String	getName()	Get the name.
Value	getValue(SessionLocal session)	Return the resulting value for the current row.
boolean	isEverything(ExpressionVisitor visitor)	Check if this expression and all sub-expressions can fulfill a criteria.
Expression	optimize(SessionLocal session)	Try to optimize the expression.

Methods inherited from class org.h2.expression.function.Function0_1

getCost, getSubexpression, getSubexpressionCount, getType, getUnenclosedSQL, mapColumns, setEvaluatable, updateAggregate

Methods inherited from class org.h2.expression.Expression

addFilterConditions, createIndexConditions, getAlias, getBooleanValue, getColumnName, getColumnNameForView, getEnclosedSQL, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getSQL, getSQL, getSQL, getSQL, getTableAlias, getTableName, getWhenSQL, getWhenValue, isConstant, isIdentity, isNullConstant, isValueSet, isWhenConditionOperand, needParentheses, optimizeCondition, toString, writeExpressions, writeExpressions

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.h2.util.HasSQL

getTraceSQL

Field Detail

RAND

public static final int RAND

RAND() (non-standard).

See Also:

Constant Field Values

SECURE_RAND

public static final int SECURE_RAND

SECURE_RAND() (non-standard).

See Also:

Constant Field Values

RANDOM_UUID

public static final int RANDOM_UUID

RANDOM_UUID() (non-standard).

See Also:

Constant Field Values

NAMES

private static final java.lang.String[] NAMES

function

private final int function

Constructor Detail

RandFunction

public RandFunction(Expression arg,
                    int function)

Method Detail

getValue

public Value getValue(SessionLocal session)

Description copied from class: Expression

Return the resulting value for the current row.

Specified by:

getValue in class Expression

Parameters:

session - the session

Returns:

the result

optimize

public Expression optimize(SessionLocal session)

Description copied from class: Expression

Try to optimize the expression.

Specified by:

optimize in class Expression

Parameters:

session - the session

Returns:

the optimized expression

isEverything

public boolean isEverything(ExpressionVisitor visitor)

Description copied from class: Expression

Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.

Overrides:

isEverything in class Function0_1

Parameters:

visitor - the visitor

Returns:

if the criteria can be fulfilled

getName

public java.lang.String getName()

Description copied from interface: NamedExpression

Get the name.

Returns:

the name in uppercase